IGHE and Alzheimer disease: Allergen sensitization, skin barrier abnormalities and type 2 immune responses (hallmarked by the differentiation of CD4+ T helper type 2 cells and the production of the type 2 cytokines, such as interleukins (IL)‐4, ‐5, ‐9 and ‐13) are considered to be key pathogenic processes contributing to AD development.3, 4 Patients with AD have also shown deregulated expression of T lymphocytes, as well as cytokines, antimicrobial peptides, chemokines, total immunoglobulin E (IgE), proteases and proteins critical for the normal structure of epithelial cells.3, 4